RF Analysis of ITER Remote Steering Antenna for Electron-Cyclotron Plasma Heating

An application of remote RF beam steering concept, based on image multiplication phenomena in a corrugated square waveguide, to electron-cyclotron plasma heating and current drive for ITER has been considered. In the present paper high attention is paid to studies of reliability of the remote steering capability in realistic waveguide condition. Different factors, could limit efficiency (RF breakdown, random technological spread of parameters, and heating of system), are simulated. Polarization properties of the remote steering antenna, arising due to non-ideal corrugation, are investigated. It is suggested a new configuration of antenna to be not sensible to corrugation parameters. RF analysis of the system, supplemented by dog-legs and a vacuum window, is also presented. A new way to use beating wave transmission in the remote steering waveguide is suggested, in order to reduce losses caused by mitre bends.